Zx-hour direct-reading clock



Feb. 14, 1956 Filed Jan. 12, 1953 E. J. UHLIG ET AL 2li-HOURDIRECT-READING CLOCK 4 Sheets-Sheet l Feb. 14, 1956 E. J. UHLIG ET AL.2,734,333

24-HoUR DIRECT-READING cLocK Filed Jan. 12, 195s 4 sheets-sheet 2 Feb.14, 1956 E, J. UHLIG ET AL. 2,734,338

24-HOUR DIRECT-READING CLOCK Filed Jan. l2, 1955 4 Sheets-Sheet 3 5 zo 425 560 5 5o 6 55 4o 7 45 5 5o 8 55 LOQUIKNNHO Feb 14, 1956 E. J. UHLIGET AL 24HOUR DIRECT-READING CLOCK 4 Sheets-Sheet 4 Filed Jan. l2, 1955pfff/vs Haz/es Deu/w 7a is I zl z z 24 I I I 3.6 liz 15s! lc -q 60 12044 oeooofoooeoo- 0500- 0 0400- 7A/6007,? npr/awww INl/ENTORS s. H L Hw.UP J. w Eo United States Patent O z4HoUR DIRECT-READnwG CLOCK Eric I.Uhlig, Haddon Heights, and Dzidris Pilsetnieks,

Westville, N. J., assignors to Wickes Engineering and ConstructionCompany, Camden, N. J., a corporation of New Jersey Application January12, 1953, Serial No. 330,704 4 Claims. (Cl. 5812s) Thisxinventionrelates to direct-reading clocks or the like, `and .more particularly todirect-reading clocks which indicate time on a 24-hour basis.

Drum-type direct-reading clocks operating on a l2- hourcycle are wellknown in the art. Such clocks normally have an hours drum with thenumbers through l2ithereon, a tens of minutes drum with the numbers 0through 5 thereon, a minutes drum with the numbers 0 through 9 thereon,and a seconds drum with indicia for numbers 00 through 59 thereon. Theseconds drum is driven, through appropriate gearing, by a synchronousmotor; and the minutes, tens of minutes and hours drums are coupled backto the seconds drum through Genevamovement mechanisms so that they moveintermittently in proper time-indicating fashion.

` Ten, or even twelve numbers of adequate size for easy reading can beput around a drum without the drum and clock case becoming excessivelylarge and bulky. A 24- hour clock with the numbers 0 through 24 arrangedon a singledrm would be so large and cumbersome as to be impractical formost applications.

As an alternative to having a single hours drum with numbers 0 through24 thereon, separate hours and tens of hours drums may be considered.The problem immediately yencountered arises from the fact that the hoursdrum must contain ten numbers but a 24-hour cycle is not evenlydivisible by ten. Therefore, the hours drum must successively indicatethe discontinuous series of numbers 0, l, 2, 3, 4, 5, 6, 7, 8, 9, 0,1,2, 3, 4, 5, 6, 7, 8, 9, 0,1, 2, 3, 4 and then 0 during one 24-hourcycle. `A very satisfactory 24-hour direct-reading clock is describedand claimed in a copending application Serial No. 292,072 filed on June6, 1952 by Eric l. Uhlig and John R. Lewis, now U. S. Patent No.2,645,896, issued on luly 21, 1953, .and assigned to the assignee ofthis application. According vto the present invention, improvements havebeen made in 24-hour direct-reading clocks which further simplify theconstruction, further reduce the cost of manufacture and further improvethe reliability. It is therefore the general object of this invention toprovide an improved 24-hour direct reading clock which combines goodlegibility with compactness in physical size.

It is another object to provide a 24-hour clock employing a mechanismrequiring a minimum number of parts.

Itis a further object to provide a clock which is reliable, simple inconstruction and relatively inexpensive to manufacture.

It is a further object to provide a clock wherein the four visiblenumbers indicating hours and minutes are of equal size and are equallyspaced so as to maximize readability.

It is a further object to provide a clock wherein the hours and minutesdrums may be reset independently without any possibility of the drumsgetting out of proper time-indicating synchronism.

Other objects and novel features of the construction and arrangement ofparts comprising this improved clock will be apparent as the descriptionof the invention progresses.

According to the present invention, separate number drums are used forthe tens of hours, hours, tens of minutes, minutes and seconds. Theseconds drum is rotated at a constant speed of one revolution per minuteby a clock motor. Geneva-movement mechanisms are interposed between thetive drums so that all drums except the driven seconds drum are rotatedwith intermittent motions in time-indicating fashion.

The hours drum, having numbers 0 through 9 thereon, is advanced onenumber (thirty-six degrees) every hour by a Geneva mechanism driven fromthe tens of minutes drum. The tens of hours drum has numbers 0, l, 2, 0,l and 2 evenly distributed over 360 degrees of its peripheral surface. AGeneva mechanism driven from the hours drum advances the tens of hoursdrum one number (sixty degrees) once in every complete revolution (tenhours) of the hours drum. The numbers 0, l and 2 on the tens of hoursdrum are repeated, and the drum makes half a revolution in twenty-fourhours. During the first ten hours, the 0 on the tens of hours drum isvisible while the numbers 0 through 9 on the hours drum are successivelyvisible. During the second ten hours, the l on the tens of hours drum isvisible while the numbers 0 through 9 on the hours drum are successivelyvisible. During the following four hours, the 2 on the tens of hoursdrum is visible while the numbers 0, 1, 2 and 3 on the hours drum aresuccessively visible. At the end of this four-hour period, the hoursdrum is advanced to make the number 4 visible and the clock then readstime 2400. At this in stant, the hours drum must be advanced 216 degreesthrough positions with numbers 4, 5, 6, 7, 8 and 9 visible to theposition showing number 0. At the same time, the tens of hours drum mustbe advanced sixty degrees from the position with the number 2 visible tothe following position with the number 0 visible. The clock will thenread time 0000, and shortly thereafter, time 0001. This recycling actionis performed as follows: A mutilated gear wheel is driven through a geartrain from the hours drum at one-third the angular displacement of thehours drum. Every third time the hours drum reaches the position withthe number 4 visible, the mutilated gear wheel reaches a position whereit can be acted upon by a mutilated gear driver driven by an auxiliaryshaft at one revolution per minute. The driver causes the mutilated gearwheel to advance seventy-two degrees, and due to the 3-to-l gearing thiscauses the hours drum to advance 216 degrees from the position with thenumber 4 visible to the position with the number 0 visible. The motionof the hours drum, acting through the conventional Geneva mecha.- nism,causes the tens of hours drum to move sixty degrees from the positionindicating number 2 to the position indicating number 0.

A more detailed description of the invention will now be made withreference to the accompanying drawings wherein:

Fig. 1 is a representation of the overall mechanism of one embodiment ofthe invention, the view being that seen from the line 1-1 of Fig. 2.

Fig. 2 is an end elevation.

F Fig. 3 is a sectional view taken on the lines 3-3 of ig. l.

Fig. 4 is a sectional view taken on the lines 4--4 of Fig. l.

Fig. 5 is a sectional view taken on the line 5-5 of Fig. l.

F Fig. 6 is a sectional view taken on the line 6-6 of Fig. 7 is arepresentation of the distribution of numbers around the various drums.

` Fig. 8 is a graphical representation of the motions of parts of themechanism which will be used in explaining the operation thereof.

Weense Fig; 9y is a front elevation showing the appearance of a 24-hourydirect-.reading clock.

Referring now in greater detail to the drawings, wherein like parts inthe several views are given the same ynumeraha frame 14'has journaledtherein a compound shaft consisting ofa mainshaft 15 and a concentricsieeve shaft 16, both shafts being freely rotatable relative to theframe and to each other. An auxiliary shaft 17 is also journalcd inframe 14 in parallel spaced relationship with the compound shaft; Aclock motor or synchronous gear motor 18k mounted on frame 14 has anoutput shaft 19 provided with a pinion 20 for driving a secondsassembly, the-drive being through a reversing pinion 11, a gear wheel 12and a ratchet 13;

The seconds assembly is freely rotatable as a unit on main shaft 15 andit' comprises a gearv wheel 21 driven by ratchet 13, a seconds drum 22with indicia thereon' as represented in Fig. 7, and a Geneva driver 23having a drive pin 24 and a locking disc ZS. Motor 18 drives the secondsassembly at the constant speed of oneV revolution per minute. Gear wheel21 drives gear 26" which is fixed on auxiliary shaft 17 so that shaft 1Talso rotates at one revolution per minute for purposes which will becomeapparent as the description proceeds.

The Geneva driver 23 drives a Geneva star wheel 29 which is freelyrotatable on shaft 17 and which has six drive slots 30 and six locksurfaces 31, the construction being shown to advantage in Fig. 3. Genevastar wheel 29 is coupled to gear wheel 32 through a spring-loaded fratchet 33, the teeth of the ratchet being arranged so thatistar wheel29 drives gear wheel 32, but the latter can be overdriven. Both arefreely rotatable on shaft 17. Once in every complete rotation of theseconds assembly,

pin 24 drives star wheel 29 and gear wheel 32 sixty de- I grecs. Thismotion is imparted to gear wheel to cause a thirty-six degree rotationof the latter, the reduction being due to the gear ratio. lt will beunderstood that Geneva mechanisms are old -in the art and that thepresent invention is not on Geneva mechanisms per se. Therefore, it willnot be necessary herein to describe the Geneva mechanism in greatdetail.

Gear'wheel 32 intermittently drives a minutes assembly including gearWheel 35, minutes drum 36 with indicia thereon as shown in Fig. 7, and aGeneva driver 37 including drive pin 38. The minutes assembly is fixedonshaft 15 as is the minutes set wheel 40. When set wheel 40 is used toset the minutes drum 36 to the proper time thel motion is nottransmitted back to the seconds` assembly by reason of the overridingaction of ratchet 33.

' Once during every revolution of minutes drum 36 and Geneva driver 37,drive pin 38 causes a thirty-six degree rotation of Geneva. star wheel42. Star wheel 42, as

shown to advantage in Fig. 4, Vconsists of a driven wheel 43 with tennotches and a lock wheel 44 having ten lock surfaces. The two-partconstruction with each part operative in a separate plane is employedbecause of the relatively large number of teeth needed. Star wheel 42 isdirectly coupled by shank 45 to gear 46; all as a unit are freelyrotatable on shaft 17. Each thirty-six degree rotation of gear wheel 46causes a sixty degree rotation of gear wheel 47 by reason of the gearratio.

Gear wheel 46 causes rotation of a tens of minutes assembly which, as aunit, is freely rotatable on main shaft 15 and which consists of a gearwheel 47, a tens. of minutes drum 48 with indicia thereon as representedin Fig; 7, and a Geneva driver 49, with drive pin 50. Driver 49 drives aGeneva star wheel 53, which is the same as star wheel 29. Star wheel 53is coupled to gear wheel 55 through spring-loaded ratchet S6. Onceduring each rotation of the tens of minutes drum 48 and driver 49, starwheel 53 and gear wheel 55 are made to rotate sixty degrees, which inturn causes a thirty-six degree rotation of gear wheel 58.

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An hours assembly is fixed on sleeve shaft 16 and it consists of gearwheel 58, hours drum 59 having indicia thereon as` represented in Fig.7, and a Geneva driver 60 having a driver pin 61.v An hours set wheel 63is also iixed on sleeve shaft 16 for setting the hours drum to thecorrect time. During the setting procedure, ratchet 56 is overridden sothat the motion is not transmitted back to the tens of minutes drum 48.f

A compound Geneva star wheel 64 is directly connected to gear wheel 65by a shank 66 andthe unit is freely rotatable on auxiliary shaft 17. Thestar wheel 64 consists of a slotted driven disk 67 and a-lock disk 68which are the same as the disks 43 and 44 of star wheel 42. Once duringevery revolution of hours. drum 59 and Geneva driver 60, drive pin 61causes a thirty-six degree rotation of Geneva star wheel 64 and gearwheel 65, which in turn causes a sixty degree rotation of gear wheel "i1and tens of hours drum 70. Gear wheel 71 and tens of hours drum 70comprise a tens ofl hoursassembly which is freely rotatable as a unit`on sleeve shaft 16. The tens of hours. drum 70 has the numbers O, l, 2,O, l, and 2 thereon as illustrated in Fig. 7.

A mutilated gear wheel 72, having teeth 73 andv 74 as shown to advantagein Fig. 5, is driven at one-third the angular displacement of the hoursdrum 59 by means of a one-toethree speed ratio gear train including gearwheel 75 fixed on sleeve shaft 16 (hours drum 59 is also xed on sleeveshaft 16), gear wheels 76 and 77` freely rotatable as a unit onauxiliary shaft 17 and a gear wheel 7 8 which together with mutilatedstar wheel 72 are freely rotatable as a unit on sleeve shaft 16. Amutilated gear driver fixed on auxiliary shaft 17 is rotated` by shaft17 at a constant speed of one revolution per minutes. Two drive pins 81on driver 80 engage the teeth 73 and 74 of mutilated gear wheel 72 attime 2400 and rotate the gear wheel 72 seventy-two degrees. This motionacting through the gear train causes a 2l6degree rotation of the hoursdrum so that it moves from the position indicating number 4 to theposition indicating number 0.

Fig. 7 illustrates the number indicia arranged around 36() degrees ofthe peripheral surfaces ofV the kvarious drums. It will be noted thatthe seconds drum. 22 has numbers for sixty seconds counting by tives,the minutes drum 36 has numbers 0 through 9, the tens of minutes drum 48has numbers 0 through 5, the hours drum 59 has numbers 0 through 9, andthe tens of hoursdrum 70v has numbers 0, 1, 2, O, 1, and, 2. The secondsdrum22 preferably has the numbers on a color coded background with 0()in the center of a red background, 15 in the center of a whitebackground, 30 in the center of a blue background and 45 in the centerof a yellow background; The numbers on all the drums are evenlydistributed thereabout. In Fig. 7 the numbers are arranged to moveupwardly past a window, whereas in the other figuresof the drawings thenumber drums move downwardly'past the window. Either arrangement of thenumbers may be used.

Fig. 9 illustrates the appearance of the clock when provided with a mask96 having windows throughwhic the numbers on the disks are visible.

The operation of the 24-hour direct-reading clock will now be describedand the chart of Fig. 8 will be used to explain the operation of thetransfer means associated with the hours drum 59 and the tens of hoursdrum 70. Motor 18 drives the seconds drum 22 through pinion 20,reversing pinion 11 and gear wheel 12 atthe constant speed of onerevolution per minute. Once duringevery revolution of seconds drum 22,minutes drum 36 is ad vanced thirty-six degrees or one-tenth of arevolution,y the motion being transmitted from Geneva driver 23 throughGeneva star Wheel 29, ratchet coupling 33 and. gear Wheels 32, 35. Onceduring every revolution of minutes drum 36 the tens ofY minutes drum 48is advanced sixty degrees on one-sixth of a revolution, the motion beingtransmitted from Geneva driver 37 through Geneva star wheel 42, shank 45and gears 46, 47. Once during each revolution of the tens of minutesdrum` 48, the hours drum 59 is advanced thirty-six degrees or one-tenthof a revolution, the motion being transmitted from Geneva driver 49through Geneva star wheel 53, ratchet coupling' 56 and gears 55, 58.Once during each revolution of hours drum 59, the tens of hours drum 70is rotated sixty degrees or onesixth of a revolution, the motion beingtransmitted from Geneva driver 60 through Geneva star Wheel 64 and gears65, 71. Drums 36, 43, 59 and 70 are normally stationary and are advancedquickly by the Geneva mechanisms from a position where one number on thedrum is visible to a position where the next higher number is visible.Drums 36, 48, 59 and 70 are thus advanced in time-indicating fashionfrom time 0001 to time 2400.

The motion of the tens of hours drum 70 is represented in Fig. 8 by adotted line, the vertical portions of which indicate the ten-hourperiods of time during which the drum` is stationary and the horizontalportions of which indicate the sixty-degree rotational shifts made bythe drum at times 1000, 2000 and 2400. The repeated numbers 0, l and 2in Fig. 8 are distinguished by prime designations. The horizontal axisof the chart indicates angular relationship relative to a fixed point onframe The motion of the hours drum 59 and gear wheel 75 is .representedin Fig. 8 by a labeled solid line having vertical portions indicatingthe hour-long periods of time during which the drum is stationary andhaving horizontal portions indicating the thrty-six degree rotationalshifts made by the drum once per hour. Mutilated gear wheel 72 is drivenfrom hours drum 59 through the gear train including gear wheels 75, 76,77 and 78. Due to the one-to-three ratio of the gear train, mutilatedgear wheel 72 is advanced twelve degrees every hour when the hours drum59 moves thirty-six degrees. Mutilated gear wheel 72 rotates 288 degreesin twenty-four hours while hours drum 59 moves 864 degrees(3604-3604444). At time 2400, mutilated gear wheel reaches a point 90 inFig. 8 Where the teeth 73 and 74 are in the path of drive pins 81 onmutilated gear driver 80 which continuously rotates at one revolutionper minute. Driver 80 then drives mutilated gear wheel 72 seventy-twodegrees. Since the driver 80 is coupled to the hours drum 59 throughgears 78, 77, 76 and 75 and sleeve shaft 16, the hours drum is rotatedthree times seventy-two degrees or 216 degrees from the position 91 withnumber 4 visible to the position with number visible. When the hoursdrum 59 moves from the position with number 9 visible to the positionwith number 0 visible, the Geneva mechanism including driver 60 and starwheel 64 causes the tens of hours drum to rotate sixty degrees from theposition with number 2 visible to the position with the following numberO visible. The transition is thus made from an indication of time 2400to time 0000 in the fraction of a minute it takes driver 80 to movemutilated gear wheel 72 through seventy-two degrees.

In setting the clock to the correct time, the minutes drum 36 fixed onmain shaft 15 is rotated by knurled wheel 40 which is also fixed on mainshaft 15. The rotation of minutes drum 36 also results in theadvancement of the tens of minutes drum 48 through the action of theGeneva mechanism 37, 42 between the drums. No more than six revolutionsof the minutes drum are needed to set drums 36 and 48 to any indicationbetween 00 and 59 minutes. The rotation of minutes drum 36 does notreact back to the second drum 22 because ratchet 33 between the drums isoverridden. An accurate setting of the seconds drum 22 is made byswitching the electricity to motor 18.

Hours drum 59 fixed on sleeve shaft 16 is set by rotating knurled setwheel 63 which is also iixed on sleeve shaft 16. The rotation of hoursdrum 59 also results in the advancement of the tens of hours drum 70through the action of Geneva mechanism 60, 64 between the drums. No morethan three revolutions of hours drum 59 are needed e i set the two drumsto any reading between 00 and 24 hours. The rotation of hours drum 59 isnot transmitted back to tens of minutes vdrum 48 by reason of ratchet 56being overridden.

Ratchet 33 has ten teeth and minutes drum 36 has ten number positions.Therefore, the resetting procedure cannot disturb the necessarysynchronous relationship between drums 22 and 36. Similarly, ratchet 56has ten teeth and hours vdrum 59 has ten number positions so as tomaintain synchronism between drums 48 and 59.

It will be noted that the Geneva mechanisms associated with the secondsdrum 22 and the tens of minutes drum 48 are identical and that theGeneva mechanisms associated with the minutes drum 36 and the hours drum59 are identical. Gear wheels 35, 46, 58 and 65 are identical, and gearwheels 32, 47, 55 and 71 are identical. This use of identical parts atvarious places in the clock mechanism reduces the number of differentparts needed and minimizes the cost of manufacture.

It is apparent that the mechanism shown and described is made up ofco-operating elements which are characterized in having a high degree ofmechanical reliability. The operation of the clock depends on Genevamovements and gear trains which are substantially trouble-free.

What is claimed is: l

l. A 24-hour direcbreading clock or the like comprising individualindicating drums for tens of hours, hours, tens of minutes, minutes andseconds, a driving motor geared to the seconds drum, Geneva mechanismscoupling the drums so that they rotate in time-indicating fashion, amutilated gear wheel, a gear train operative to drive said mutilatedgear wheel from the hours drum at onethird the speed thereof, and amutilated gear driver driven at a constant rate from said motor, saiddriver being positioned to engage said mutilated gear Wheel at apredetermined one of its positions and rotate it substantially 72degrees, whereby said hours drum is driven by said mutilated gear wheelthru said gear train.

2. A 24-hour direct-reading clock comprising individual indicating drumsfor tens of hours, hours, tens of minutes, minutes and seconds, adriving motor geared to the seconds drum, Geneva mechanisms coupling thedrums so that they rotate in time-indicating fashion, a mutilated gearwheel, gear coupling between said hours drum and said mutilated gearwheel so that the latter moves onethird the distance of the former, anda mutilated driver driven from said motor, said driver being positionedto engage said mutilated gear wheel at a predetermined one of itspositions and rotate it substantially 72 degrees to cause asubstantially 216-degree rotation of said hours drum.

3. A 24hour direct reading clock comprising individual indicating drumsfor tens of hours, hours, tens of minutes, minutes and seconds, adriving motor geared to the seconds drum, Geneva mechanisms coupling thedrums so that they rotate in time-indicating fashion, a mutilated gearwheel, gear coupling between said hours drum and said mutilated gearwheel so that the latter moves onethird the distance of the former, anda mutilated gear driver driven from said motor, said driver beingpositioned to engage said mutilated gear wheel every third time thenumber 4 is visible on the hours drum and quickly rotate the mutilatedgear wheel and the hours drum through positions with the numbers 4through 9 visible on the hours drum.

4. A 24-hour direct-reading clock comprising individual indicating drumsfor tens of hours, hours, tens of minutes, minutes and seconds, adriving motor geared to the seconds drum, Geneva mechanisms coupling thedrums so that they rotate in time-indicating fashion, a mutilated gearwheel, a three-to-one gear coupling from the hours drum to saidmutilated gear wheel, and a mutilated gear driver driven from saidmotor, and operative through said mutilated gear wheel and gear couplingto quickly ad Vance said hours drum through the positions with thenumbers 4 through 9 visible every hird time the number 4on the hoursdrum is visible.

References Cited in the le of this patent UNITED STATES PATENTS2,355,514 Deane et a1. Aug. 8, 1942 2,636,339 Holzner 2 Apr. 28, 19532,645,896 Uhlig et al July 21, 1953

